The family of a paranoid schizophrenic who killed both his parents has said they want to ensure that other families take action before mental illness turns to tragedy.

Julian Cuddihy (43) was found not guilty by reason of insanity of the murder of his mother Kathleen (73) and father James (77) at their home in Churchtown, Carndonagh, Co Donegal, on October 22, 2014.

Julian's brother James Jnr said that the case was a tragedy "for all our family, in particular our beloved parents, Jimmy and Kathleen, but also for our brother Julian".

He said that the family tried to get professional help for Julian - but decisive actions were not taken that would have prevented the tragedy.

"We hope that nothing like this will ever happen to another family. We would urge families with similar concerns about the mental well-being of a family member to seek timely assistance and intervention."

The trial heard how Julian Cuddihy believed his mother was trying to poison him. During interviews with consultants after the killings Mr Cuddihy revealed notions the IRA was trying to recruit him and that aliens were reading his mind.

Ms Justice Margaret Heneghan said she would like to extend her "deepest sympathies" to the Cuddihy family. She committed Mr Cuddihy to the Central Mental Hospital in Dundrum.

He will return to court on June 20 when a doctor will suggest a course of ongoing care.